Boiling Point Determination Using Capillary Tube

It is important to use technique is known as a mixed melting point determination. The sample is placed in the opening in a capillary tube alongside a mercury thermometer and allowed to be heated by the oil as it circulates through the Thiele tube. Chapter 03: Chapter 3 of Chemistry Lab Manual (EN) book - its purity. ❖ To add a manual tag at any point in the melting point determination, pause the video playback, select Tube 1, 2 or 3 then touch ‘ADD A TAG’. Student Lab Guide Revision Date: 09/2019 5 Dry Test Tube (this will be used later to determine the Boiling Point of the unknown)!! 12. Figure 3(a) shows the Thiele tube apparatus, filled to the base of the neck with silicone oil or mineral oil. The capillary has a rough edge at the cut end, which serves as a surface at which bubbles can form during. Loading Capillary Tube. Ultramicro Boiling-point Determination. Procedure (A)To determine the boiling point of water. Fill a capillary melting point tube to a depth of 0. At the microscale level, the boiling point of a liquid may be determined using only 3-4 µL of liquid 1. A boiling chip may be added to the liquid in the test tube to avoid bumping or uneven boiling of the liquid. How to Use a Thiele-Dennis Tube continued 2 21 linn ientii n ll ihts esee 6. Used for melting point and boiling point determination. (Your instructor will weigh out 0. The sample is heated by an oil or heating block. You might miss it if you aren’t watching carefully the whole time it is cooling because it gets slurped up like a straw very quickly. 0 Ethyl acetate 75. KIM3450599: Kimble ® melting point capillary case of 20 × 100 ea (2000 total), borosilicate glass, O. To seal an end just touch the outer layer of flame from a microburner. 6 Carbon disulphide 46. Capillary tubes allow visual observation of melting/boiling points of very small amounts of substances, while providing an thermally insulated carrier. Melting point capillary tubes 7. Melting Point Determination When doing a melting point determination, be careful to avoid contamination with impurities. The test was conducted as per the test guideline OECD 103. Place its contents inside the closed tube using the following procedure. accuracy acetate alkali allowed amount angle aniline apparatus bath benzene benzoic acid boiling boiling tube boiling-point bottle bridge wire bulb burette calculated calibration calorimeter capillary tube carbon carried cell cent Chem chloride concentration conductivity connected constant cork cubic centimetres degree of hydrolysis determined. Note: Boiling point of refrigerant is a function of pressure, Thus the change in pressure in the compressor and capillary makes it to be able to change the phase. Boiling is a key heat transfer process for a variety of power generation and thermal management technologies. Melting point can be measured in an electronic melting point machine or by using a practical set up where the capillary tube is strapped to a thermometer immersed in some heating oil. The melting point is then determined using a melting point apparatus (as in Figure) that simultaneously heats both the sample tube and a thermometer. fats, oils and waxes, an inner slip melting point capillary tube containing a column of sample is immersed in water, which is then heated at a specific rate. formulations. The capillary tube which is sealed end up was immersed in the sample. However, when we measure the boiling points for these compounds, we find that they are dramatically higher than the trends would predict, as shown in Figure 10. The BHT should be level with the bulb of the thermometer. sc, demonstrator in botany, bedford college, london. Since the slope = - AHvap/R, we find the heat of vaporization as follows: slope = - AHvap/K —» AHvap = - slope x R then J —> kj. MDHS72, is a laboratory method using pumped solid sorbent tubes, thermal desorption and gas chromatography. remember to use a new melting point capillary tube for each melting point determination. Bunsen burner 4. 3 for discussion. Introduction In this laboratory you will identify an unknown compound by using mixture melting points. 26: Time-lapse entry of liquid into the capillary tube. Determination of Melting Points of Benzoic Acid. Experiment 1 - Melting Points pg. The boiling range for crude oil may exceed 1000 °F. Because the evaporation/boiling phenomenon is a complicated and dynamic process, the determination of the critical meniscus radius is quite challenging. H2SO4 : As per need. The variables for the concentric tubes capillary tube-suction line heat exchanger are the same, with the addition of capillary tube external diameter. This document specifies a method for the determination of the boiling range distribution of petroleum products. The capillary melting point method is done by heating the capillary tube filled with test substance to 10 degrees below the expected temperature, and. It is best to mark the position of the extremity of the mercury column when the bulb and stem are surrounded by steam, at the same time noting the height of. Physical and Physicochemical Methods: 1. This is the most common piece of apparatus for determining melting point (as shown in the picture at the top of the page). Cottrell apparatus is used for finding elevation of boiling point. (9) Weighing boats or metal weighing pan. For simple, automatic, recorded results. Use this solution. If you do not have at least 1 mm of sample, scoop another small portion and repeat. Determination of molar mass of solute. P): Aim :-To determine the boiling point of an organic compound (liquid) Apparatus :-Thiele's tube , capillary tube , Stand ,thread, Bunsen burner. Crush the solid substance into a fine powder using the end of a test tube and a watch glass. Some substance will enter into it. [This is not an issue in this experiment, but in the future you will want to determine the melting point of a solid you have just separated from a liquid by filtration. Determination of melting temperature and melting range of Pulverizable 68 substances 69 70 The melting range of a substance is the range between the corrected temperature at which 71 the substance begins to collapse or form droplets on the wall of a capillary tube and the. 2 Determination of melting temperature, melting range, congealing point, boiling point, and boiling range: 1. This paper focuses on the two-phase flow model in a capillary tube for low and moderate values of heat flux q=5×10 3 −5× 10 4 W/m 2. 56 (Mean VP of Antoine & Grain. Contaminated sample, results in low melting point. The pure compounds in the graph show the smallest melting range and. Place the Bunsen burner about 3–4 inches below the Thiele tube. Using this method viscosity of water, methanol, ethanol, benzene, acetone, and chloroform were measured at room temperature using marine barometer tubing. The Melting Point M-560 is designed for manual determination of melting and boiling points. Melting point apparatus. The Determination of Melting Points. where ∆T is the freezing-point lowering or boiling-point elevation, K is molal freezing (or boiling) constant which is specific for each solvent, m is the molality of the solution (number of moles of solute /kg of solvent). You use the smallest amount so that you can make multiple observations, and it melts closest to its true melting point. Each chemical compound will have a specific boiling point. T = Rρgh / 2 cos θ. The boiling point of the liquid depends upon the pressure exerted upon the liquid surface. To assist refiners in determining D86 boiling range data AC Analytical Controls developed the AC 8634 application. The temperature that favors the transformation of. , make a fast determination to ascertain the approximate melting point (fast heating rate) and then cool the melting point apparatus below the roughly determined melting point (approx. 5 Detection of Gas Odourants 3. Posted by ann on Sunday, October 17, 2010 at 4:26am. This test method uses capillary columns with thin films, which results in the incomplete separation of C 4-C 8 in the presence of large amounts of carbon disulfide, and thus yields an unreliable boiling point distribution corresponding to this elution interval. 5-10oC lower) and make a slow, careful determination using the other capillary and applying 1°C per minute heating rate. The most commonly a heated metal block such as a Mel-Temp apparatus. Experimental Procedures. Purification of Naphthalene by Sublimation 1. The Boiling point of a liquid is an important physical property. 4 Thermal Desorption Using Tenax (0 Analysis of Petrol (ii) Analysis of Ethanol 3. Levitt determined the viscosity of liquids using the half-time of rise in a fine vertical capillary. Make a test tube assembly by using the following directions and illustration. The Aspirin crystals should be firmly packed, and fill the capillary tube to a depth of no more than 1-2 mm. melting point of a compound using capillary tubes and a digital melting. Control of almost any type of sample by measuring melting point, boiling point or slip melting point. Place approximately 0. Fahrenheit scale Temperature scale that is used in some English-speaking countries, on which the freezing point of water is at 32 and the boiling point at 212. Why do you use a new capillary tube for melting point determination each different melting and boiling points. Unless otherwise specified, it is assumed that a boiling point is for 1 atm of pressure. Thermometer (0 o-60 C. Methods of Measuring Melting Point. To seal an end just touch the outer layer of flame from a microburner. In this setup, an empty glass capillary tube is inverted into a container of the pure compound in the liquid phase. 0 Chloroform 61. The rotor holds balanced centrifugal tubes of equal amounts of the solid-liquid mixture. Melting point capillary tubes are made of KIMAX-51 glass. Solution 11 class 12 chemistry (Determination of molar mass using elevation in boiling point). Flash point and boiling point are the important physical property of the flammable liquids, and are important parameters to evaluate their combustion behavior. one end of the tube will be sealed. The Determination of Melting Points. boiling point voltage Prior art date 1966-07-29 Legal status (The legal status is an assumption and is not a legal conclusion. The capillary attraction between the inside of the capillary melting point tube and the outside of the capillary pipette is greater than that inside the pipette, so the sample is easily transferred into the larger tube. Some representative constants, boiling points, and freezing points are given in Table 1. Insert a 1. The average of the two readings gives the melting point of the substance. Experimental setup: Procedure to determine the boiling point of Benzene: Take a capillary tube and close its one end by holding the end in the flame and rotate it for 2-3 minutes. Remove the stopper with care and then clamp this tube in a hot water bath to melt the solid lauric acid. The boiling point of a liquid varies according to the applied pressure; the normal boiling point is the temperature at which the vapour pressure is equal to the standard sea-level atmospheric pressure (760 mm [29. Determination of Boiling Point (B. A capillary tube is a very thin tube made of a rigid material, such as plastic or glass. 0 Ethyl acetate 75. Solution 11 class 12 chemistry (Determination of molar mass using elevation in boiling point). This is the most common piece of apparatus for determining melting point (as shown in the picture at the top of the page). Determination of molar mass of solute. The original Büchi glass components guarantee uniform wall thickness at the sides and ends of the tubes and capillaries. the actual sample tube. The sample is placed in the opening in a capillary tube alongside a mercury thermometer and allowed to be heated by the oil as it circulates through the Thiele tube. Crush the solid into a fine powder by means of a clean spatula or the fire polished end of a glass stirring rod. 1 Melting point determination according to the pharmacopoeia 19 3. 2 Anizol 155. Fill a capillary melting point tube to a depth of 0. MELTING POINT DETERMINATION PURPOSE Identify an unknown compound by its melting point. The boiling point will increase as a result of the different branching of the OH, the melting. If on placing the sealed capillary tube in the test tube, the liquid is seen rising in the capillary tube, it indicates that the capillary tube is not properly sealed. If you're behind a web filter, please make sure that the domains *. Automated melting point determination procedures are generally included. When a satisfactory melting point range has been determined, choose a known substance that has a melting point within 5°C of the observed value. Procedure (A)To determine the boiling point of water. Boiling points can be determined using the technique of simple distillation. ) With the Höppler viscometer the density must be known in order to calculate the dynamic viscosity. sion of the capillary, e. The determination of microscale boiling points in a melting-point tube may be simplified by replacing the micro-bell bubbler with an ultrathin capillary tube bubbler. Make a test tube assembly by using the following directions and illustration. Several simplifying assumptions are adopted in the model: • The two-phase flow is steady; •. Like melting points, boiling points are characteristic properties of pure materials. In a boiling point determination experiment, what function does the inverted capillary tube perform?. There are many liquids which are miscible with other liquids and mixtures have fixed boiling points (azeotrope). Water wants to stick to the glass and surface tension will push the water up, until the force of gravity prevents further rise. Description: The Melting Point M-565 is for automatic determinations of both melting and boiling points and is designed for true, professional quality control. The height of liquid in a tube due to capillarity can be calculated. The method of capillary melting point determination involves placing a small amount of sample in the bottom of a narrow capillary tube that has been closed at one end. The Thiele tube may also be used to determine boiling points, by using a. Ghanbaripour 2 Thus, the boiling point is the temperature range over which enough energy is provided to a liquid compound so that its molecules can separate sufficiently to transform to a gaseous state by breaking non-covalent interactions. Determination of molar mass of solute. Use of digital temperature sensor and display makes these units more accurate, safer and easy-to-use. This preboiling vaporization tends to broaden boiling endotherms, may exhaust the specimen before the actual boiling point, or can self-pressurize a sealed specimen. fats, oils and waxes, an inner slip melting point capillary tube containing a column of sample is immersed in water, which is then heated at a specific rate. However, when we measure the boiling points for these compounds, we find that they are dramatically higher than the trends would predict, as shown in Figure 10. Heat the bath until the temperature is about 30 below the expected melting point. The pharmacopeias regard the capillary method as the standard technique for melting point determination. Requirements - Given Solid Substance, Capillary Tube, Paraffin, Laboratory thermometer. Results and Discussion: From the class melting point data, the melting point diagram was constructed (Table 1). Since no pores in a practical filter element are likely to be shaped like capillary tubes it is necessary to introduce a shape correction factor K into the. is to be determined insert a capillary tube in it, one end of it is sealed well. Determination of melting temperature and melting range of pulverizable substances. Buy and find information on Büchi B-540/B-545 boiling point tubes from Sigma-Aldrich. A clean glass capillary tube having a diameter of. The original Büchi glass components guarantee uniform wall thickness at the sides and ends of the tubes and capillaries. The initial and final melting points were recorded. ) In practice, the melting point test is carried out on a small amount of finely powdered substance contained in a length of 1. Rinse the pipette and add a small amount of. 0cm in length to ensure that they can be retrieved from the sample block. Capillary tubes must be a minimum of 5. (10) Plastic bag. Preparing the Sample. 1) You isolated the following compounds in lab and observed the melting points in the table below. Use caution in increasing the temperature gradually, as not to miss the correct boiling point and alter the data. Keep the lower end of the capillary tube and the thermometer at the same level. In the second determination, the sample. Fill the micropycnometer to the top with distilled water using the distilled water bottle. When a liquid rises in a capillary tube, the weight of the column of the liquid of density ρ inside the tube is supported by the upward force of surface tension acting around the circumference of the points of contact. Position the client. 5 mm diameter capillary tubing which has been sealed at one end by melting in a gas flame. Place about 5 cm3 of the unknown liquid in the boiling tube. 5 g of impure naphthalene into a 100-mL beaker. Unknown k was distilled using the technique of simple distillation once it was distilled a portion of the distillate was used to determine the boiling point using the capillary tube boiling point technique. Description: These single use, glass capillary tubes can be used for storage of small amounts of liquids or for the determination of melting point. 0368578(p-760)-0. Determination of melting temperature and melting range of Pulverizable 68 substances 69 70 The melting range of a substance is the range between the corrected temperature at which 71 the substance begins to collapse or form droplets on the wall of a capillary tube and the. Up to 8 manually tagged values can be added for each capillary. MDHS72, is a laboratory method using pumped solid sorbent tubes, thermal desorption and gas chromatography. The end of the capillary tube melts and seals itself. There are many techniques namely, crystallisation, distillation sublimation, chromatography etc. (10) Plastic bag. Repeat the measurement two more times and take the average of the three values. Determination of Molar Mass by Boiling Point Elevation of Urea Solution June 9, 2016 Dr. 5 mm diameter capillary tubing which has been sealed at one end by melting in a gas flame. Water wants to stick to the glass and surface tension will push the water up, until the force of gravity prevents further rise. It is accepted as an index of purity as pure solids have well-defined melting points whereas presence of impurities can result in a spread of melting point temperature. Because the evaporation/boiling phenomenon is a complicated and dynamic process, the determination of the critical meniscus radius is quite challenging. Make a test tube assembly by using the following directions and illustration. Knowing the system pressure, it is possible to use various methods to estimate the boiling point at reduced pressure fro m the atmospheric pressure boiling point. The physical properties of a substance can be used to establish its purity. Be sure to record the temperature to the nearest 0. Ultramicro boiling-point determination Insert a “glass bell”. 3 /C at atmospheric pressure. Predicted data is generated using the US Environmental Protection Agency’s EPISuite™. A melting point of the recrystallized compound will be taken in order to determine the purity. The normal vapor pressure, then, is the temperature at which the vapor pressure is 760 torr, or exactly 1 atm. 1Methods of melting point determination 15 3. After a Melting point determination, why can't you re-use the solidified substance and capllary tube for subsequent determination? asked by Nuke on March 11, 2012; Chemistry. Place about 0. When the solid begins to melt, record the temperature of the oil. For an accurate determination of a melting point & boiling point, the quality of the used tubes and capillaries is decisive. Boiling Point 1. A partial immersion thermometer, calibrated for 75 mm, is specified in most methods for the determination of melting poin. The volume of your liquid product in the melting-point capillary tube should not exceed one- half of an inch. Capillary action is an important ability of water to move through other materials. Measuring Boiling Points 1. If you're behind a web filter, please make sure that the domains *. Dispose of the solids as directed by your instructor. The Determination of Melting Points Melting points will be determined by using one of the DigiMelt units (Figure 1. Using gloves, carefully break a closed-end capillary tube in half and place it in a microscale test tube with the closed end up 2. In the evaporation/boiling process from a capillary. Melting point range for 1-tetradecanol: 37-40 degrees Celsius Melting point range for mixture: 34-37 degrees Celsius. Add a few CaCl2 pellets to this tube and let stand for 5-10 minutes - the solution should clear up as the CaCl2 absorbs any remaining water (" dries the solution" ). Samples are separated in GC based on differences in vapor pressure (boiling point) and interaction with a stationary phase. Samples were packed tightly prior to melting point determination. The purpose of this experiment is to determine the boiling points of various organic compounds and to use these to identify unknowns. Do you want to read the rest. Now tap the sealed end of the capillary tube on the porous plate gently. Record your observations of the liquid level in the tubes. Bunsen burner 4. The temperature range over. Melting point has been defined as the temperature at which a solid changes state from solid to liquid. Which nursing measure is essential to the clients nursing care? A. The boiling points of these substances differ by no more than 6°C, and some of them even have the same. Water is not the only liquid that can do this, but its properties make it better at capillary action than most. Place the capillary tube into the melting point apparatus and turn the heating stage on. Special precautions must be taken when sampling for this analyte by Method 0030. 3 /C at atmospheric pressure. This problem is important in the context of improvement of heat transfer in cooling systems of electronic devices with high power density. However, not all compound s fal ling into this category can be determined. Determination of Melting Points According to Pharmacopeia Stanford Research Systems Phone: (408) 744-9040 USP Standards The US Pharmacopeial Convention is the recommended source of CRSs for US Pharmacopeia protocols. remember to use a new melting point capillary tube for each melting point determination. Insert the packed melting point tubes into a melting point apparatus. Heating too fast. Fluids 17, 062107 sufficiently small, a point can be reached beyond which the. Make a test tube assembly by using the following directions and illustration. Add a few CaCl2 pellets to this tube and let stand for 5-10 minutes - the solution should clear up as the CaCl2 absorbs any remaining water (" dries the solution" ). Life Science; Chemicals. Lab experiments on Boiling point elevation and freezing point depression BOILING POINT ELEVATIONS FOR SOLUTIONS OF BENZOIC ACID IN ACETONE Hold each test tube in a water bath and record at which temperature the solution boils. Place the capillary in the melting point stage and turn on the power and allow the hot-stage temperature to rise fairly rapidly to within 15-20 o C below the expected melting point of the compound. For an accurate determination of a melting point & boiling point, the quality of the used tubes and capillaries is decisive. Boiling point determination for an unknown liquid: Add approximately 5 mL of an unknown liquid to a 25 x 200 mm pyrex test tube. Objective: The objective of this experiment is to determine the molar mass of an unknown solute by measuring the freezing point depression of a solution of this solute in a solvent as compared to the freezing point of the pure solvent. These devices are used as scientific instruments to determine the melting point of a substance. 1 Determining the melting point in the capillary tube 16 3. including proper packing of a sample in a melting point capillary tube, precise determination of the melting point range of a sample. Estimate the Van Deemter equation constants by regression analysis. Thermometer. 1Methods of melting point determination 15 3. It wets the wall of capillary of the thermometer. Flash point and boiling point are the important physical property of the flammable liquids, and are important parameters to evaluate their combustion behavior. Thermophysical property data for liquid lithium at temperatures approaching the normal boiling point are. observation at some known fixed point in addition to 00 and 1000 C. Some representative constants, boiling points, and freezing points are given in Table 1. The Melting Point M-560 is designed for manual determination of melting and boiling points. Modern refrigerants with a temperature glide of 10 °F (5 °C) or higher use dew point (DP) Note: Liquid receivers are not typically used on refrigeration systems, which commonly rely on capillary tubes or fixed metering devices. Crush the solid substance into a fine powder using the end of a test tube and a watch glass. To find the boiling point at 650 mm Hg, simply subtract 4°C from the normal boiling point. P): Aim :-To determine the boiling point of an organic compound (liquid) Apparatus :-Thiele's tube , capillary tube , Stand ,thread, Bunsen burner. Theory- The change from solid to liquid state of a compound in heating is called melting and the temperature at which a solid in its pure form melts is called the melting point. IMPORTANT: Note that unlike boiling point, the melting point is relatively insensitive to pressure and no pressure correction needs to be made. 2 Use of Dragar Tubes OnSite to detect Gas Odourants. 3 for discussion. Since its expansion rate is non-uniform 2 December 2018 at 05:36. Boiling points are useful physical properties for indicating the purity of an organic compound. Melting point and boiling point are examples of such physical characteristics, and provide useful information, especially when the samples measured are pure compounds. After the preparation of capillary tubes and through the adaptation of simplified Siwoloboff method, few drops of pineapple wine sample were placed in a centrifuge tube. Use a Pasteur pipet to transfer most of the lower CH2Cl2 layer to a small test tube. The mounting of the. The temperature range over. then introduced into the flow-tube part of the apparatus through the side tube to the left of C, and made to flow round to the other side through a fine capillary tube D of internal diameter 0. Of course, the utility of a capillary tbe is limited to the temperature range it c. Advanced Chemistry: Boiling Point Determination Name: Procedure: 1. Up to three samples can be viewed and tested at any one time. According to these measurements the boiling point of water between 660-and 860-mm pressure is given by the equation t=100+0. Introduction In this laboratory you will identify an unknown compound by using mixture melting points. Since water is transparent and the reading cannot be seen. Thermometer (0 o-60 C. Then add 10 grams NaCl to the hot water. (a) Keep the lower end of the capillary tube and the thermometer at the same level. Melting point determination Put about 2-3mm of sample in the bottom of the capillary tube and put the tube into the. Another portion of 1 ml was used to figure out the density of unknown hydrocarbon K. student perform 2 melting point determinations on a crystalline product. For use with Model M-560/M-565 melting point apparatus. Table 1 gives the boiling points of a number of substances at normal external pressure—that is, at a pressure of 760 mm Hg, or 101,325 newtons/m 2. Gas chromatography and thermodynamics are the basis of the 8634 analyzer. You will determine the melting points of pure benzoic acid, succinimide and trans-stilbene. Used for melting point and boiling point determination. ❖ Touch the appropriate tag. Apparatus: Matches, Isopropyl (Rubbing) Alcohol, 1-2 small rubber bands, Thermometer, Powdered Acetamide beaker, 2 closed-end capillary tubes (melting point tubes), 10-12 mm diameter test tube, Heat source. Boiling by inserting an upside-down melting-point capillary tube into a small test tube which will be attached to your highest temperature thermometer with a The test tube will be heated using. 23a) and heated inside a. However, during the determination of the actual melting point range, the temperature should not rise more rapidly than 2 or 3 o per minute. Place a small quantity (1/16 inch in tube) of the solid to be melted in a capillary tube (labeled melting point tubes). In this methodology, a thin glass capillary tube. 5 mL (2 cm) of the liquid in the microscale test tube using a pipet. Chapter 03: Chapter 3 of Chemistry Lab Manual (EN) book - its purity. 01 °C for Δ 9-THC. The tubes are used to collect samples of liquids, which will flow up into the tubes against the effects of gravity in a process called capillary action. Use this solution. The melting point of a compound is the temperature at which the solid phase and. Have enough to ¼ fill a boiling tube for each student. Capillary tubes (1 box) 15. Mercury is opaque and bright, so the movement of mercury inside the capillary tube is easily visible. Precautions. Very often, the pharmacopeias also list special methods for difficult or unusual cases of melting point determination. Of course, the utility of a capillary tbe is limited to the temperature range it c. Boiling chips 3. In a boiling point determination experiment, what function does the inverted capillary tube perform?. There are many liquids which are miscible with other liquids and mixtures have fixed boiling points (azeotrope). In the other determination, the sample height is 4-5 mm and the melting range is found to be 141-145 degree C. Tubes and Bottles; Chromatography. Capillary action is also known as capillarity, capillary motion, or wicking. Melting point capillary tubes 7. The method of capillary melting point determination involves placing a small amount of sample in the bottom of a narrow capillary tube that has been closed at one end. Save the sample for further use 3) Boiling point determination Set up a hot water bath using a 250mL beaker Begin heating the water in the beaker Obtain a ~10mL sample of the unknown in a clean, dry test tube Add a boiling stone to the test tube with the unknown Open the computer interface software, using a graph and digit display. Crush the solid into a fine powder by means of a clean spatula or the fire polished end of a glass stirring rod. mate the capillary pressure for multiple wire-mesh screens, for both sintered and simple contact situations. In determination of melting point range why is it necessary to position the capillary tube next to the thermometer bulb? Because there is a possibility that the thermometer will be receiving more energy than the compound and you can get melting points higher than we ought to be getting. It checks 5 degrees above and below the known melting point. QUESTIONS: DETERMINATION OF MELTING POINTS. Because mercury has low thermal capacity, high heat conductivity, inertness in relation to a glass capillary tube and a high boiling point, it is an. The mounting of the. To find the boiling point at 650 mm Hg, simply subtract 4°C from the normal boiling point. High pressure capillary Viscometer This apparatus is used for the determination of the viscosity of single phase reservoir fluids and related systems. Place about 0. 1 Investigation of a Suitable Absorbent for the Analysis of Gas 3. The most commonly a heated metal block such as a Mel-Temp apparatus. Determination of the Boiling Point. The photocell gives a stop signal to a digital indicator reading out the temperature measured by a resistance thermometer located in the. Place the small portion of capillary sealed end up into the boiling-point sample in the test tube. This ensured uniform heating throughout the sample and sharper melting point range. So mercury level indicates the temperature as quickly as possible and accurately. Capillary – This instrument equipped with three holes for an arrangement of holding 100 mm long capillary for testing the samples in testing heating media. Trial 1 Boiling Average value = (81 C + 78 Trial 3 81 C) Trial 2 78 77 C + 77 C)/3 C Observations: 1. !Given a sample of a eutectic mixture containing 60. A well-defined melting point is only given for 100 percent pure substances. Determination of the cold filter plugging point (CFPP) of diesel and domestic heating fuels using either manual or automated test equipment (both of which are suitable for referee purposes). Define boiling point how does this definition describe what is occurring in micro boiling point determination method? (i. 4 Sealing a melting point capillary tube. Thermometer. The capillary has a rough edge at the cut end, which serves as a surface at which bubbles can form during. Ultramicro boiling-point is a method to determine the boiling point of a liquid and is similar to that of melting point determination. Of course, the utility of a capillary tbe is limited to the temperature range it can handle. Discrimination may occur when injecting samples onto gas chromatography capillary columns, whereby peak areas for higher boiling point compounds are smaller than they should be compared to lower boiling compounds. The open end is pressed into fi ne crystals of the substance and the turned upside down and Beaker containing benzoic acid dissolved in. Do you want to read the rest. They are commonly used in medical and research fields to extract very small samples of liquids to be analyzed, such as blood samples for. The Melting/Boiling Point Apparatus are used for determining the boiling point of liquids and melting point of solids. Obtain a glass capillary tube. After the preparation of capillary tubes and through the adaptation of simplified Siwoloboff method, few drops of pineapple wine sample were placed in a centrifuge tube. Determination of Boiling point. To estimate the melting point for Δ 9-THC, the group contribution method developed by Constantinou was used because it was the prediction method that was most accurate for predicting CBD's melting point. your unknown components, and (3) the names, structures, literature boiling points, and refractive indices of the known compounds that most clearly agree with your measured boiling points. This will lead to a lower melting point. There are many liquids which are miscible with other liquids and mixtures have fixed boiling points (azeotrope). Ultramicro Boiling-point Determination. Since the slope = - AHvap/R, we find the heat of vaporization as follows: slope = - AHvap/K —» AHvap = - slope x R then J —> kj. Sample Probe must be located at points where LNG is in a sub-cooled condition. The end of the open end capillary should be level with the thermometer bulb. Using remelt sample can affect various factors in the determination of boiling point experiments. 11 "The Phenomenon of Capillary Action". 2 Determination of melting temperature, melting range, congealing point, boiling point, and boiling range: 1. Dispose of the solids as directed by your instructor. Heat the bath until the temperature is about 30 below the expected melting point. ] The correct determination of the boiling point of a thermometer is a matter of greater difficulty. You must have ebullation to concentrate at atmospheric pressure--use a boiling stone, a capillary tube, or agitation. Heat the tube with a Bunsen burner. melting point of a compound using capillary tubes and a digital melting. Capillary tubes must be a minimum of 5. The Thiele tube may also be used to determine boiling points, by using a. [This is not an issue in this experiment, but in the future you will want to determine the melting point of a solid you have just separated from a liquid by filtration. When the amount the liquid is small, Siwoloff’s method (capillary tube method) is used. Melting point determination The sample inside the capillary tube should be 2~3 mm in height Glass tube for knocking the capillary tube should be kept clean and dry; wash and oven dry after class Record the melting range of sample Replace the capillary tubes in the second run Recrystallization. Melting Point Determination. When large volumes of liquids are available, It consists of a central tube with a constriction and twodistillation is the method of choice for boiling point finger-like projections close to the neck. 4 Thermal Desorption Using Tenax (0 Analysis of Petrol (ii) Analysis of Ethanol 3. Corning PYREX Capillary Melting Point Tubes are made from Code 7800 glass with an inside diameter range from 1. Boiling in capillary tubes The aim of the present work is to study the effect of heat flux and mass flow rate on the structure and the thermo-hydrodynamic characteristics of flow in a heated capillary tube. Obtain a glass capillary melting point tube, which has one end sealed and the other end open. This document does not apply to gasoline samples or gasoline components. However, on the Moon the height would be six times greater. In this setup, an empty glass capillary tube is inverted into a container of the pure compound in the liquid phase. Gas chromatography and thermodynamics are the basis of the 8634 analyzer. Mercury is available in pure form. ACD/Boiling Point calculates the boiling point for a compound, from 0. A partial immersion thermometer, calibrated for 75 mm, is specified in most methods for the determination of melting poin. Determination of Molar Mass by Boiling Point Elevation of Urea Solution June 9, 2016 Dr. Determination of the cold filter plugging point (CFPP) of diesel and domestic heating fuels using either manual or automated test equipment (both of which are suitable for referee purposes). PROCEDURE Fasten the capillary tube containing acetanilide to the thermometer with string or a rubber bond so that the sample is close to and on a level with the center bulb of the thermometer bulb. 99 ISO/TC 34/SC 11. Experiment #1 Melting Point Page 2 Figure 1 - Melting Point Using Thiele Tube Filling the Capillary Tube Make sure the sample is dry. Chemistry Lab Report Purpose The purpose of this lab is to determine the identity of an unknown liquid by measuring its density and its boiling point and try to match it with those solutions given in Table 2 of experiment 2. Typically, the more volatile a compound is, the lower its boiling point. The Capillary Method to Determine Boiling Point. Determination of melting temperature and melting range of pulverizable substances. 00000001621 (P-760)3, in which t is expressed in degrees centigrade (Int. Boiling point determination A sample in a fusion tube is attached to a thermometer with a rubber band, and immersed in the tube. [An experimental determination of the zero point of a thermometer using procedure above. Fill a round bottom flask to half its capacity. Visit ChemicalBook To find more Ceftiofur(80370-57-6) information like chemical properties,Structure,melting point,boiling point,density,molecular formula,molecular weight, physical properties,toxicity information,customs codes. The end of the open end capillary should be level with the thermometer bulb. For filling the substance make a heap of the powdered substance on the porous plate. Automatic Programmable Melting Point Apparatus Model: µThermoCal100 | Make: ANALAB | HSN Code: 90278090 Supplied with Melting Capillary One End Sealed (Pack of 100 Nos. After some time, water starts to boil again although no more heat has been provided to it. The temperature range over which. Closed end capillary tubes. Fahrenheit scale Temperature scale that is used in some English-speaking countries, on which the freezing point of water is at 32 and the boiling point at 212. Use caution when working with the Mel-Temp apparatus as it can become very hot!. 3 Boiling point The boiling point of a liquid is the corrected temperature at which the liquid boils under normal atmospheric pressure when determined by the method described below. This test method is limited to samples having a minimum initial boiling point of 37°C (99°F), a maximum final boiling point of 285°C (545°F), and a boiling range of 5 to 150°C (9 to 270°F) as measured by. The determination of microscale boiling points in a melting-point tube may be simplified by replacing the micro-bell bubbler with an ultrathin capillary tube bubbler. The solid sample is sealed inside the capillary and placed inside the apparatus. The boiling point of the liquid depends upon the pressure exerted upon the liquid surface. Using a melt point capillary tube, insert enough chemical to produce about a 1-2 mm height of chemical in the sealed end of the capillary tube after forcing it to the bottom. (11) Test tube brush. It has gained prominence in the past half-century because its accumulation in the body has been linked to increased risk and occurrence of atherosclerosis and cardiovascular disease. The Boiling point of a liquid is an important physical property. Take a small quantity of the compound whose melting point is to be determined on a porous plate and powder it with a spatula. This paper focuses on the two-phase flow model in a capillary tube for low and moderate values of heat flux q=5×10 3 −5× 10 4 W/m 2. Invert the tube, and tap it on the lab bench so the crystals fall to the bottom (the closed end) of the tube. Take the melting point of pure urea and cinnamic acid. !Why should you always use a new capillary tube when performing a second melting point determination on your sample? 3. using a micro pipet fill about 1 / 2 inch of a melting point tube with sample insert a Bell capillary tube, open end down push the Bell capillary down into the liquid with a section of a long capillary tube. The temperature that favors the transformation of. To use a nomograph, simply line up the normal boiling point at 760 mm Hg with the pressure for the new measurement and find out how much to subtract from the normal boiling point. A Mel-Temp works by going through a range of possible melting points. Melting Points Do calibration of the thermometer using naphthalene (80-82°C). 5 g of sample as a demonstration; with a spatula. 33 g ml-1 (20°C) and solubility in water at 20°C is 1 kg kg-1. Boiling Point •Boiling point is the temperature at which vapor pressure of liquid equals surrounding pressure •Boiling point of water at sea level at atmospheric pressure is 100 °C –Boiling point in Denver is ~94 °C –Boiling point at top of Mt. This is the most common piece of apparatus for determining melting point (as shown in the picture at the top of the page). That this is so may be easily proved by altering the rate at which air enters through the capillary tube ; the more rapid the introduction of air the lower will be the observed temperature, and unless the amount of air is exceedingly small the observed boiling point will be sensibly too low. Melting point and Boiling point determination Aim: To determine the boiling point of a liquid and to determine the melting point of a solid. These temperatures are typically used in the calibration of thermometers and are known as the fixed points. 001 torr to 7600 torr. 6 Carbon disulphide 46. represents the energy required to overcome the various intermolecular attractions binding the molecules as a liquid (e. The tube may be open (called tubular or capillary) or filled with a divided inert support material (a packed column). Each mixture was placed in a closed-end capillary tube, labeled and the melting point determined using a Mel-Temp. The temperature range over. A Mel-Temp works by going through a range of possible melting points. Cottrell apparatus is used for finding elevation of boiling point. To raise its boiling point to 0 /C, the pressure must be increased to 430. From your question just you want to say that, why we don't used remelt sample or just cool and solidify the sample and again used for determination of boiling point. It is defined as the temperature at which the vapor pressure of the liquid exactly equals the pressure exerted on it. MELTING POINT - CAPILLARY METHOD The melting point determined by the capillary method is the temperature at which the last solid particle of a compact column of a substance in a tube passes into the liquid phase. T = Rρgh / 2 cos θ. Using the file, carefully cut a piece 3 to 4 cm long, measuring from the closed end of the tube. Place the tube on a ceramic hot pad to cool before use. The boiling point determination of test chemical was done following OECD Guideline 103 and according to the method of Siwoloboff. Chemicals :-Pure given organic compound, liquid paraffin. The temperature range over which. Boiling Point Determination Setup (Accurate Method) Retrieved from: The distillate was used for the last part of the experiment which involves the determination of the boiling point of ethyl acetate using the accurate method. Determination of melting temperature and melting range of pulverizable substances. Melting point has been defined as the temperature at which a solid changes state from solid to liquid. PROCEDURE Fasten the capillary tube containing acetanilide to the thermometer with string or a rubber bond so that the sample is close to and on a level with the center bulb of the thermometer bulb. Continue to r educe so heating rate is on 1°C/min when within 15°C of expecte d melt. Rinse the pipette and add a small amount of. SMP11, Analog Melting Point Apparatus. student perform 2 melting point determinations on a crystalline product. The commercial availability of highly purified solvents has largely eliminated problems with solvent impurities, although high costs, solvent toxicities, and restrictions on spent solvent disposal must be considered. Boiling by inserting an upside-down melting-point capillary tube into a small test tube which will be attached to your highest temperature thermometer with a The test tube will be heated using. Determination of Boiling point. As the temperature of the water bath reaches the melting point of thePDB , it will begin to melt. KD1168 Dilatometer, 0-2mL in 0. Improved capillary gas-chromatographic-mass spectrometric method for the determination of anabolic steroid and corticosteroid metabolites in horse urine using on-column injection with high-boiling solvents. 99 ISO/TC 34/SC 11. The capillary has a rough edge at the cut end, which serves as a surface at which bubbles can form during. Once you've reached the boiling point, reduce the heat slightly to keep the water boiling. Homocysteine, a non-protein amino acid, is an intermediate in the metabolism of methionine and biosynthesis of cysteine. Place the capillary in the melting point stage and turn on the power and allow the hot-stage temperature to rise fairly rapidly to within 15-20 o C below the expected melting point of the compound. The boiling point of a liquid is the temperature at which vapour pressure of the liquid becomes equal to the atmospheric pressure, which the surface of the liquid experiences. Students are presented with a short lesson on the difference between cohesive forces (the forces that hold water molecules together and create surface tension) and adhesive forces (the forces that causes water to "stick" to solid surfaces. Using the file, carefully cut a piece 3 to 4 cm long,. 5 g of impure naphthalene into a 100-mL beaker. Melting point capillary tubes 7. Crush the solid substance into a fine powder using the end of a test tube and a watch glass. As the liquid approaches its boiling point, a few bubbles will be observed flowing out of the end of the capillary tube. 10 microliters (enough to fill the capillary to a depth of ca. Place its contents inside the closed tube using the following procedure. To fill a melting point tube, tap the open end of the tube into your powdered sample to pick up a few grains. Furthermore, the measurement is easily made with a small quantity of material Obtain a capillary tube from your instructor, and. Pahlavan / Dr. The test was conducted as per the test guideline OECD 103. Thermophysical property data for liquid lithium at temperatures approaching the normal boiling point are. MATERIALS •Mel-Temp melting point apparatus •capillary tube •unknown sample •Table of Melting Point Data •laboratory notebook THEORY The melting point (mp) of a substance is one of the physical properties that chemists use to identify a substance. The method of capillary melting point determination involves placing a small amount of sample in the bottom of a narrow capillary tube that has been closed at one end. See figure 3. ) With the Höppler viscometer the density must be known in order to calculate the dynamic viscosity. The most common and most basic method of determination is the capillary method. The ASTM D86 and D1160 standards describe a simple distillation method for measuring the boiling point distribution of crude oil and petroleum products. Manufacturer of Glass Capillaries & General Labware - Melting Point Capillary, 75 or100 mm long, Capillary Tubes, Tapered Plastic Plugs For Glass Joint and SS Needle Aspiration Reusable Needles Long Needle offered by Spectrum Marketing, Mumbai, Maharashtra. A clean glass capillary tube having a diameter of. Melting point apparatus consists of metallic heating block made to receive three capillary tubes and a stem thermometer at a time. Boiling point determination A sample in a fusion tube is attached to a thermometer with a rubber band, and immersed in the tube. Load dried caffeine reference powder into a capillary tube and tap the capillary tube on a hard surface until the sample packs into the bottom. 1 mm INNER DIAMETER, AND APPROX. Levitt determined the viscosity of liquids using the half-time of rise in a fine vertical capillary. Melting Point Determination. ----- FIGURE i—APPARATUS FOR THE DETERMINATION OF MELTING AND BOILING POINT (JISK 0064-1966), WITH SPECIFICATIONS IN MILLIMETERS A: MEASURING TUBE B: CORK STOPPER C: VENT D: THERMOMETER E: AUXILIARY THERMOMETER F: BATH LIQUID G: SAMPLE TUBE; MAX. mate the capillary pressure for multiple wire-mesh screens, for both sintered and simple contact situations. Be sure to record the temperature to the nearest 0. , make a fast determination to ascertain the approximate melting point (fast heating rate) and then cool the melting point apparatus below the roughly determined melting point (approx. Obtain a glass capillary melting point tube, which has one end sealed and the other end open. IMPORTANT: Note that unlike boiling point, the melting point is relatively insensitive to pressure and no pressure correction needs to be made. 50 mL of ethyl acetate was placed inside the distilling flask after rinsing it with the sample. A Mel-Temp works by going through a range of possible melting points. ) With the Höppler viscometer the density must be known in order to calculate the dynamic viscosity. Too large of an amount of solid will result in a larger melting point range, and should be avoided. A tiny fragment of porcelain is placed in the tube and the solvent evaporated to about 0. To determine the melting point of benzoic acid, using a spot plate and the butt end of a test tube or a mortar and pestle, grind the sample of benzoic acid into a fine powder. Use of the Melting Point Apparatus 1. The thermometer with a capillary tube attached using rubber tubing; Use the bunsen burner to heat the mineral oil slowly. Sometimes they are white. Capillary tubes Capillary tubes are supplied either with one sealed end, two sealed ends or two open ends. Melting point and Boiling point determination Aim: To determine the boiling point of a liquid and to determine the melting point of a solid. 7 Ammonia 33-7 3 2 Amylalcohol (iso) 131. 10: a) Depositing sample into the open end of a capillary tube, b) Inverting and tapping the tube on the benchtop, c) Dropping the sample through a long tube, d) Correct height of sample in the tube. That is the melting point. This is done using a realistic capillary tube apparatus similar to what students might use in the laboratory. Determination of the Boiling Point. …Set: Melting Point M-565 Includes: Melting Point M-565 instrument, Sample Loader M-569, 100 melting capillaries, 10 boiling tubes, 10 boiling capillaries, calibration set M-560/565, sample holder, packing wire and cleaning tool. Preparing a Sample of Melting Point Determination Melting point samples are prepared in a capillary tube that is closed on one end (a melting point capillary). BOILING POINTS AND MELTING POINTS PART 2 Name: Grethel Zegarra Date of Lab: October 26, 2010 Date lab is due: November 2, 2010 HYPOTHESIS The boiling point in degrees Celsius will increase as the number of carbon atoms increase. It is not commonly used these days because of its toxicity. In determination of melting point range why is it necessary to position the capillary tube next to the thermometer bulb? Because there is a possibility that the thermometer will be receiving more energy than the compound and you can get melting points higher than we ought to be getting. Obtain a sample of pure lauric acid in a sealed test tube. Melting Points Do calibration of the thermometer using naphthalene (80-82°C). Then, the sample capillary was immersed in a boiling point tube containing water (Figure 1). A sealed capillary, open end pointing down, is placed in the fusion tube. Compact the solid to the bottom of the tube by dropping it several times. Control of almost any type of sample by measuring melting point, boiling point or slip melting point. 2 Thermodynamic determination of melting points 20. A small amount of the test item was filled in a capillary tube and was heated in the electronically temperature controlled sample block. Procedure: Fill a melting point capillary tube with the sample of interest by thrusting the open end into the powder several times. By using different oils, different temperature ranges can be reached and used to determine melting points. Place a small quantity (1/16 inch in tube) of the solid to be melted in a capillary tube (labeled melting point tubes). Using a melt point capillary tube, insert enough chemical to produce about a 1-2 mm height of chemical in the sealed end of the capillary tube after forcing it to the bottom. 0 cm section. According to these measurements the boiling point of water between 660-and 860-mm pressure is given by the equation t=100+0. Any sealable plastic bag large enough to contain the ground sample being no more than 2/3 full and thick enough to resist tearing. It is considered as solid state and liquid phases are in equilibrium. There are many techniques namely, crystallisation, distillation sublimation, chromatography etc. The centrifuge consists of a centrifuge tube holder called rotor. Boiling point helps identify and characterise a compound. Take a glass capillary tube of about 5-6 cm in length and seal one end of it. Determination of Melting Points According to Pharmacopeia Stanford Research Systems Phone: (408) 744-9040 USP Standards The US Pharmacopeial Convention is the recommended source of CRSs for US Pharmacopeia protocols. The temperature previously recorded and this current temperature is the boiling point range. Dispose of the liquid as directed by your instructor. Why is Boiling point important? June 24, 2011, Hari M, Leave a comment. Place about 1 mL of your liquid in a small test-tube. The temperature range over which. pdf), Text File (. Packing of the powder should be uniform without any large air gaps in between the solid particles. I was instructed to record a melting point range for each compound, rather than a single melting temperature of different polymers">temperature melting point. Figure 3(a) shows the Thiele tube apparatus, filled to the base of the neck with silicone oil or mineral oil. Melting point of a sample was determined by electric melting point apparatus. The pharmacopeias regard the capillary method as the standard technique for melting point determination. Determination of melting temperature and melting range of pulverizable substances. Boiling points are useful physical properties for indicating the purity of an organic compound. …Set: Melting Point M-565 Includes: Melting Point M-565 instrument, Sample Loader M-569, 100 melting capillaries, 10 boiling tubes, 10 boiling capillaries, calibration set M-560/565, sample holder, packing wire and cleaning tool. Melting Point Determination: The melting points of drug substances are used in the identification of the substance, as well as to determine substance purity and the presence of contamination. !Why is it necessary to allow the Mel-Temp to cool before performing a second melting point determination? 4. Make a test tube assembly by using the following directions and illustration. Thus, surface tension; Where, h - height of the liquid column above the liquid meniscus ρ - Density of the liquid r - Inner. The BHT should be level with the bulb of the thermometer. Laboratory Exercise: Melting and Boiling Points In this exercise we will determine the melting point of the substance Salicylic Acid, a precursor to Aspirin, and the boiling point of n-Propoanol, a cousin of Grain Alcohol. Executive summary:. Experiment 1: Colligative Properties Determination of the Molar Mass of a Compound by Freezing Point Depression. (Why?) Determination of Solubility Place approximately 50 mg of solid (about the amount that will fit on the tip of a spatula) into a small test tube. The sample is loaded in a sealed capillary tube and the temperature gradually raised by means of an internal metal block. H2SO4 : As per need. accuracy acetate alkali allowed amount angle aniline apparatus bath benzene benzoic acid boiling boiling tube boiling-point bottle bridge wire bulb burette calculated calibration calorimeter capillary tube carbon carried cell cent Chem chloride concentration conductivity connected constant cork cubic centimetres degree of hydrolysis determined. When these thermometers are placed in warm solutions, they can measure the temperature of that solution using the expansion of the liquid inside the bulb through the capillary tube. The photocell gives a stop signal to a digital indicator reading out the temperature measured by a resistance thermometer located in the. Then, the sample capillary was immersed in a boiling point tube containing water (Figure 1). Modify the semi-microscale apparatus (Figure 13. The liquefaction point is a physical property of a substance. Thermometer (1 each) 1. remember to use a new melting point capillary tube for each melting point determination. In a minimum boiling azeotrope, a mixture of A and B codistill at a boiling point that is lower than the boiling point of either A or B alone. Water has high boiling and freezing point. Determination of Boiling Point (B. 72 °C, and its melting point is -38. Unless otherwise specified, it is assumed that a boiling point is for 1 atm of pressure. Disposable pipets. Melting point tubes are available with both ends open or for improved circulation rates, one end sealed. As the temperature increases, the sample turns from a solid to a liquid. Without professional equipment like spectrometers or chromatographs, melting and boiling points become essential tools for identifying and testing compounds for purity. Use this solution. Experiment 1 - Melting Points pg. The Boiling Point Method Determination of Ethyl Acetate In the determination of the boiling point of ethyl acetate using the rough method, a et-up for simple distillation was prepared. Melting point apparatus. In the second determination, the sample. Then, the switch of the Mel-Temp device was turned on, and the capillary tube was inserted in the device. The extremely fine tube (narrow bore) of a thermometer is called a capillary. Heat the water on a Bunsen burner or other heat source until it reaches the point of boiling. This preboiling vaporization tends to broaden boiling endotherms, may exhaust the specimen before the actual boiling point, or can self-pressurize a sealed specimen. A liquid boiling point is the temperature when its vapor pressure is equal to the atmospheric pressure. Ultramicro boiling-point is a method to determine the boiling point of a liquid and is similar to that of melting point determination. The thermometer with a capillary tube attached using rubber tubing; Use the bunsen burner to heat the mineral oil slowly. The interaction between cohesive forces and adhesive forces causes the well-known capillary action.

azg072nrbu03r, 68apxizvl4sc7, vjdncyca9qim3, bqx7ybhytjo73zx, tupeecfk8dnaey, u9l9iptvzd, 4xycp6eoayzk, jpw2vflizbni, tbyg3sm0iby, xw2px0yiprn, l1fw02crccdzfd, 6i81anhm4lu5c3b, hj0mydz0f9sq, 0eq8behydu7p0lp, 2cju1a97j3g, 9xs7zampco4, q5iroeh5amn9l1, khihxn5cbnldhv, sj80tetv4s2, 8uihj82crt5njx, hbwx0d8cp8enc1, 2n6w41pg1qt, o4wx443t3x5yyc, 1p7xni1bu4, 62hrsia8fns4, n80iw9asiw5b, 3uel9sgpd1hpppp, ph9507puyi6, 135eusashfs, y14bzbm2ca83k, 53dr2t1rdc, yi5pg6ayb3c, qanfnmvg3jzu, npbblmt9pyo, osxwzoz0gbviy8u